Table 1.

Studies included in a systematic review of the literature on conflict of interest owing to authors’/investigators’ affiliation with industry associated with their research

Study	Year	Discipline	Purpose	Source	Finding
Leopold et al.15	2003	Orthopedic	Assess potential association between research outcome and external factors, including industry funding	Article review in 3 orthopedic journals published between July 1999 and June 2000	Industry-funded studies were significantly more likely to report positive outcome than non–industry funded studies
Okike et al.16	2007	Orthopedic	Investigate the association between different types of conflict of interest and study outcome	Podium presentation review at a national orthopedic annual meeting in 2001 and 2002	Authors with a conflict of interest (e.g., royalties, stock options, consulting/employee status) were more likely to report positive outcome
Bhandari et al.17	2004	Surgery	Determine whether association between industry funding and conclusions are generalized to surgical specialties	RCTs published between January 1999 and June 2001 in 8 surgical and 5 medical journals	Industry funding was significantly associated with statistically significant proindustry results; variations in study quality or sample size did not explain proindustry findings
Zuckerman et al.4	2004	Orthopedic	Determine the frequency and type of self-reported conflict of interest between orthopedic research and industry	Final program from a national orthopedic annual meeting in 1985, 1988, 1992, 1997, 1999 and 2002	Industrial research support increased significantly between 1995 and 2002; the proportion of support to individual authors rather than to institutions increased signficantly
Ezzet18	2003	Orthopedic	Define the prevalence of commercial funding in adult lower extremity research and correlation of funding with reported outcomes	Presentations at 2002 national orthopedic meeting and journal articles published in 2001 in 3 orthopedic journals	Research sponsored by industry was more likely to report a proindustry outcome than studies funded independently
Lynch et al.19	2007	Orthopedic	Determine if nonscientific variables, including commercial funding, are associated with positive outcomes and acceptance for publication	Manuscripts on hip and knee arthroplasty submitted to JBJS from January 2004 to June 2005, excluding resubmissions, reviews, case reports, editorials and basic science studies	Industry-funded studies were not more likely to conclude a positive outcome, and positive outcome was not more likely to be published; however, non– positive outcome studies were of higher quality, which suggests an insidious bias against publication; industry-funded studies were more likely to by published
Shah et al.20	2005	Spine	Evaluate association between industry funding and positive research finding	Articles published in Spine from January 2002 to July 2003	Industry-funded studies demonstrated a greater likelihood to report positive results than studies funded independently
Cunningham et al.21	2007	Orthopedic	Assess potential association between nonscientific factors (funding source), scientific factors (study design) and positive study outcome	Abstracts presented at a national orthopedic annual meeting in 2004	Commercial funding was associated with positive outcomes, but those studies did not have better designs or larger samples than non–industry funded studies

JBJS = Journal of Bone and Joint Surgery; RCT = randomized controlled trial.